Benfabriken



UNITED STATES PATENT OFFICE.

WVILLIAM PFITZINGER, OF ELBEREELD, GERMANY, ASSIGNOR TO THE FAR-BENFABRIKEN, VORMALS FR. BAYER & 00., OF SAME PLACE.

SUBSTANTIVE YELLOW DYE.

SPECIFICATION forming part of Letters Patent No. 428,629, dated May 27,1890. Applieation filed September 12, 1889. Serial No. 328.764.(Specimena) Patented in France June '7, 1889, No. 198,786-

To all whom it may concern.-

Be it known that I, WILLIAM PFITZINGER, chemist, a subject of theEmperor of Germany, residing at Elberfeld, Prussia, Germany, haveinventedcertainnewandusefulImprovements in the Manufacture of New YellowDirect- Dyeing Coloring-Matters, (for which I have obtained LettersPatentin France, dated June 7, 1889, No. 198786;) and I do herebydeclare IO the following to be a full, clear, and exact description ofthe invention, such as will enable others skilled in theart to which itappertains to make and use the same.

The invention relates to the manufacture of substantive or direct-dyeingcoloring-matter or dyes, and has for its object to produce such dyesfrom those thio derivatives of paratoluidine, metaxylidine, and pseudocumidine.

that are obtained by melting these bases with sulphur until theevolution of hydrogen sulphide ceases, those thio derivatives derivedfrom paratoluidine having been described'by Gattermann J acobsen, Ber.XXII, p. 330-442.

I have discovered that new dye-stuffs are formed by the diazo compoundsof the thio bases referred to when combined with their sulpho-acids orby combining the diazo compounds of the sulpho-acids with the free basesthemselves or the sulpho-acids of said free 0 bases. All thesedye-stuffs or coloring-matters have the property of dyeing unmordantedcotton in an alkaline bath. The best results are obtained withdye-stuffs derived from the 'thioparatoluidines. They dye cotton a fine3 5 greenish yellow, while those dye-stuffs derived from the thioderivatives or products of metaxylidine and pseudo cumidine impart amore reddish-yellow color to cotton.

In carrying out my invention I proceed in 40 general as follows: First,the diazo compounds of the thio derivatives referred to are combinedwith an acetic-acid solution of the sulpho-acids of said thio bases;secondly, the

diazo compounds of the sulpho-acids are combined with an acetic-acidsolution of the said thio bases or their sulpho-acids, and, lastly,

the thio bases are combined with thio bases or their sulpho-acids insolution in acetic acid.

The resulting mixtures are allowed to stand for some days at atemperature of from 20 to 30 centigrade, and are thereafter slowlyheated to 60 or 80 centigrade untilasample dissolves in alkaline water.The dye-stuffs are then heated to boiling, neutralized with sodiumcarbonate, and the dye-stuffs separated in a well-known manner by meansof common salt and dried.

Having described the process as generally carried out, I will nowdescribe it more specifically, to wit:

D ye-stuifs from the thioparaioluidin e, melting at 191 centigrade, andthe sulph0-acid thereof 1 diazotize with a solution of ten kilograms ofsodium nitrite at a temperature of from 30 to 40 centig'rade, thirty-onekilograms of thioparatoluidine sulphate, called dehydrothioparatoluidineby Jacobsen and melting at 191 centigrade. The diazo compound obtainedis poured into an acetic-acid solution of twenty-five kilograms ofthiopara- 7o toluidine sulpho-acid, which can be obtained bysulphonating the thioparatoluidine at 191 centigrade. A deep blackprecipitate is formed under continuous stirring, and the temperature isthen raised to from 20 to 30 centigrade, and the mixture left standingfor about two days at a temperature of from 60 to cent-igrade, when theblack precipitate will turn to a clear orange shade. If it dissolveswith a fine yellow color when boiled in 80 alkaline water, the mixtureis heated to boiling, neutralized with sodium carbonate, treated withcommon salt, and the precipitate fi1- tered off and dried. The resultingdye-stuff dyes cotton a fine greenish-yellow shade.

Dye-stuyj from thioparatoluidine sulphoact'ds.-If thioparatoluidine,which melts at 191 centigrade, is sulphonated, a sulpho-acid is obtainedthat can readily be diazotized and then caused to react onthioparatoluidine sulo pho-acid and a beautiful green-yellow dyestuffobtained. In this case I proceed as follows: The diazo compound ofthirty-five kilos of thioparatoluidine sulpho-acid is poured into anacetic-acid solution of twenty-five kilos of a like thioparatoluidinesulpho-acid, andthe mixture is treated exactly as described in referenceto the first example hereinabove given.

Other thio derivatives than dehydrothioparatoluidine or its sulpho-acidsmay be used and similar results obtainedas, for instance, the thioderivatives of paratoluidine, called priniulin base or primuline, orthose thio products which have as yet not been exactly defined ordescribed, as the thio products of nietaxylidine or pseudo eumidineobtained by heating" the bases with sulphur.

Having described my invention I clainr- 1. The process for manufacturingdirect yellow dyeing coloring-1natters deriving from the thioderivatives of paratoluidine, meta- Xylidine, and pseudo cu1nidine,whichconsists in combining the diazo compounds of the thio derivatives ofparatoluidine, inetaxylidine, and pseudo cuinidiue or those of theirsulphoacids with the sulpho-acids of the thio derivatives ofparatoluidine, lllOi'ilXYlidlllO, and pseudo cuinidine, substantially asdescribed.

The process for manufacturing direct .YOHOW dyei11gcoloring-1natters,deriving from the thio derivatives of paratoluidine, metaxylidine, andpseudo cuinidine, which consists in combining the diazo compounds of thesulphoacids of thethio derivatives of paratoluidine, lnetaxylidine, andpseudo culnidine with the thio derivatives of paratoluidinenietaxylidine, and pseudo cumidine, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

\VILLIA PFIIZINGER.

Vitnesses:

Amen KEUTER, Jiunss M.

